To date, when a sample of bodily fluid is collected from an individual for testing of the presence of a parasitic infection, best results are obtained when the sample is smeared on a slide, stained and viewed under a microscope. Only trained medical personnel having sufficient experience are able to perceptively detect and correctly identify the presence of parasitic infection.
This process is labor intensive, as it is performed manually, and thus a low throughput is achieved. PCR or immunological testing may be performed as well. These processes are not suited for general health clinics which may be located in third-world countries, and thus may not have proper laboratory equipment for preparing a sample, viewing it, or testing it.
The need exists for an apparatus which automates identification of parasitic or microbial infection, allowing rapid diagnosis. Such an apparatus is essential especially in locations which may not have trained medical personnel or a full-laboratory for processing of bodily fluids, or where high-throughput screening is desired.
Additionally, blood banks worldwide do not have the capability to test blood donations for many parasitic infections. While typically, some bacterial and viral infections, such as hepatitis, HIV, and others, are tested for, there are currently no rapid tests in use for parasitic infection of blood donations, other than for detection of a single parasitic species, Trypanosoma cruzi, which causes Chaggas Disease.
To exemplify the need, there are no established rapid tests for Malaria, which throughout the tropics and sub-tropics worldwide. There are similarly no rapid tests for Babesiosis, an emerging disease caused by the pathogen Babesia duncani or B. microti. Babesiosis is endemic to the US, particularly New England. The transmitting vector is a tick (that also transmits Lyme disease). Though Babesiosis infection is mostly asymptomatic in healthy adults, if it is transmitted through transfusion of an infected blood unit, it may be fatal in immunocompromised, splenectomized or elderly recipients. There is no FDA-approved test to date for the disease. Numerous authors have underscored the need for screening blood donations for these parasites. The problem of transfusion-based parasite transmission is expected to gain dramatically increasing significance, owing to globalization and international travel.
Hence, there is a need for an automated apparatus capable of inspecting blood donations or blood samples for the presence of microbial or parasitic infection. Such an apparatus should be capable of rapidly testing samples in a short time-frame, with minimal human involvement.
Parasites represent a group of extremely abundant human pathogens, which is estimated to infect around one third of the world population. These diseases are source of immense suffering and millions of deaths annually worldwide. In the US alone 11 million new cases of parasitic infections are diagnosed each year. The economic burden imposed by parasitic infections is immense and impossible to calculate.
The “gold standard” for diagnosis of most types of parasites is manual identification under a microscope of stained smears of biological fluids. Most frequently, peripheral blood, is used, or in other instances, lymphatic fluid and cerebrospinal fluid (CSF). This method is laborious and requires highly trained personnel, and as a result it is typically low-throughput and expensive. Despite that, microscopic analysis remains the most sensitive and specific method for the diagnosis of many parasitic diseases, including malaria and babesiosis. According to the World Health Organization, a patient is to be certified as free of malaria after a trained technician observes no parasites by examining 100 images of a “thick” peripheral blood smear at 100× magnification.
Additional prior art methods for detecting parasites are based on immunological or PCR tests. All such methods that are in use today are either laborious and/or expensive, preventing their use in high-throughput screening applications. For example, many versions of malaria-testing “dip sticks” have recently been described. While these may be used for initial screening in remote locations, they are not usable, for example, in blood-bank screening, as their high false positive rates would result in too many parasite-free samples to be discarded. Even when immunological and PCR tests yield a positive result, the patient's blood is most often tested by the microscopic method for conformation.
The need exists for an automated apparatus capable of inspecting blood donations or blood samples for the presence of parasitic infection. Such an apparatus should be capable of rapidly testing samples in a short time-frame, with minimal human involvement.
It would therefore be desirable to provide an apparatus for rapid detection of pathogens, and especially parasites, in bodily samples, which may be used by minimally trained personnel and which provides a high throughput.